16 17-isoxazolino-delta-1 3 5(10)-gonatrienes

ABSTRACT

16A,17A-ISOXAZOLINE STEROIDS OF THE FORMULA   2-R2,3-(R1-O-),13-Z,16,17-(-CH=N-O-),17-(R-O-)   GONA-1,3,5(10)-TRIENE   WHEREIN R AND R1 ARE SELECTED FROM THE GROUP CONSISTING OF HYDROGEN, ALKYL OF 1 TO 7 CARBON ATOMS AND ACYL OF AN ORGANIC CARBOXYLIC ACIDS OF 1 TO 18 CARBON ATOMS, R2 IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND HALOGEN AND Z IS ALKYL OF 1 TO 4 CARBON ATOMS AND THEIR PREPARATION AND NOVEL INTERMEDIATES. THE INVENTION ALSO INCLUDES HYPOCHOLESTEROLEMIC COMPOSITIONS HAVING NO SUBSTANTIAL ESTROGENIC ACTIVITY.

United States Patent "ice 3,629,245 16,17-ISOXAZ0LIN0-A- -G0NATRlENESDaniel Bertin, Montrouge, and Lucien Nedelec, Clichysons-Bois, France,assignor to Roussel-UCLAF, Paris, France N 0 Drawing.Continuation-impart of application Ser. No. 556,796, May 9, 1966. Thisapplication July 7, 1969, Ser. No. 839,660

Claims priority, application Japan, May 14, 1965, 40/17,103; Aug. 11,1965, til/28,020 Int. Cl. C07c 173/10 US. Cl. 260-23955 7 ClaimsABSTRACT OF THE DISOLOSURE 160:,l7uc-iSOX21ZOliIl6 steroids of theformula wherein R and R are selected from the group consisting ofhydrogen, alkyl of 1 to 7 carbon atoms and acyl of an organic carboxylicacids of 1 to 18 carbon atoms, R is selected from the group consistingof hydrogen and halogen and Z is alkyl of 1 to 4 carbon atoms and theirpreparation and novel intermediates. The invention also includeshypocholesterolemic compositions having no substantial estrogenicactivity.

PRIOR APPLICATION The preesnt application is a continuation-in-partapplication of our copending, commonly assigned US. patent applicationSer. No. 556,796 filed May 9, 1966, now abandoned.

PRIOR ART US. Pat. No. 3,213,084 describes the preparation of various3,16,17-trisubstituted-A -estratrienes including in Example I17a-hydroxy-3-methoxy-A -estratriene-[16,8,17fi,-d]-A -isoxazo1ine whichcompounds are described as having estrogenic activity. Moreover, thepatentees of the said patent described in the Journal of OrganicChemistry, Vol. 30 (1965), pages 22342238 the physiological activity ofthe said compound of Example I of their patent. They stated that thesaid compound was a particularly potent estrogenic agent having auterotropic effect in rats at the 37 oral dose level, about six timesthat of estrone.

OBJECTS OF THE INVENTION It is an object of the invention to provide thenovel 16a,17a-isoXazoline steroids, of Formula I.

It is another object of the invention to provide a novel process for thepreparation of the 16a,17a-isoxazolino steroids of Formula I.

It is a further object of the invention to provide novel intermediatesfor l6u,l7a-isoxazolino steroids of Formula I.

It is an additional object of the invention to provide novelhypochole'sterolemic compositions without estrogenic activity.

It is another object of the invention to provide a novel 7 method forthe treatment of hypercholesterolemia in animals.

3,629,245 Patented Dec. 21, 1971 These and other objects and advantagesof the invention will become obvious from the following detaileddescription.

THE INVENTION The novel compounds of the invention are16a,17uisoxazoline steroids of the formula OR 10 Z l R, g'on wherein Rand R are selected from the group consisting of hydrogen, alkyl of 1 to7 carbon atoms and acyl of an organic carboxylic acids of 1 to 18 carbonatoms, R is selected from the group consisting of hydrogen and halogenand Z is alkyl of 1 to 4 carbon .atoms. R may be a halogen such asfluorine, chlorine, bromine and iodine.

The acyl radical of the organic carboxylic acid having 1 to 18 carbonatoms may be derived from an aliphatic, aromatic, cycloaliphatic orheterocyclic carboxylic acid. Examples of suitable acids are alkanoicacids, such as formic acid, acetic acid, propionic acid, butyric acid,isobutyric acid, valeric acid, isovaleric acid, trimethyl acetic acid,caproic acid, fl-trimethyl propionic acid, heptanoic acid, caprylicacid, pelarginic acid, capric acid, undecylic acid, lauric acid,myristic acid, palmitic acid and stearic acid; alkenoic acids such asundecylenic acid, linoleic acid, ricinoleic acid and oleic acid;cycloalkyl carboxylic acids such as cyclopentyl carboxylic acid,cyclopropyl carboxylic acid, cyclobutyl carboxylic acid and cyclohexylcarboxylic acid; cycloalkyl alkanoic acids such as cyclopentyl aceticacid, cyclohexyl acetic acid, cyclopentyl 4O propionic acid andcyclohexyl propionic acid; arylalkanoic acids such as phenyl acetic acidand phenyl propionic acid; aryl carboxylic acids such as p-phenylbenzoic acid, p-cyclohexyl benzoic acid, benzoic acid and2,4-dinitrobenzoic acid; phenoxy alkanoic acids such as phenoxy 4 aceticacid, p-chlorophenoxy acetic acid, 2,4-dichlorophenoxy acetic acid,4-ter-butylphenoxy acetic acid, 3- phenoxy propionic acid and 4-phenoxybutyric acid; heterocyclic carboxylic acids such as furane-Z-carboxylicacid, S-ter-butylfurane-Z-carboxylic acid, S-brornofurane- 2-carboxylicacid and nicotinic acids; fl-ketoalkanoic acids, such as acetylaceticacid, propionylacetic acid and butyrylacetic acid; amino acids such asdiethylaminoacetic acid and aspartic acid.

The novel process of the invention for the preparation 55 of thel6a,l7a-isoxazo lino steroids of Formula I c0rn prises reacting in anacidic media a l6-hydroxymethylene- 13,8-Z-A- -gonatriene-17-one of theformula wherein R R and Z have the above definitions with a compoundselected from the group consisting of hydroxylamine and its acidaddition salts to form a A '-(4,5- 16a,17a)-isoxazolino-l3,B-Z-A-gonatriene-17 3-01 of the formula :CHOH

wherein R R and Z have the above definitions and the 17-hydroxy group isetherified by reaction with an alkyl halide having 1 to 7 carbon atomsor esterified with an esterifying derivative of an organic carboxylicacid of 1 to 18 carbon atoms such as the acid halide or the acidanhydride to form a compound of the Formula I.

The isoxazolino derivative is obtained by the general method foroxazoles by condensation of hydroxylamine or an acid addition saltthereof such as its hydrochloride with a fl-diketonic grouping,preferably in the preesnce of an organic solvent as a lower alkanol,i.e., methanol, ethanol, etc.

The 16-hydroxymethylene-l3-Z-A -gonatriene-17- ones of Formula II, whichare the starting materials, can be prepared by reacting thecorresponding 13-Z-A gonatriene-17-one with a lower alkyl formate suchas ethyl formate or methyl formate in the presence of a base such as analkali metal alcoholate, an alkali metal hydride or an alkali metal inan organic solvent. The organic solvent may be one or more alkanols suchas methanol, ethanol, etc.; aromatic hydrocarbons such as benzene,toluene, etc.; dialkyl substituted amides of carboxylic acids such asdimethyl formamide; heterocyclic bases such as pyridine; or ethers suchas ethyl ether, dioxane, tetrahydrofuran, etc.

There are four different possible isomeric forms of 16,17-isoxalinesteroids of the general formula US. Pat. 3,213,084 describes producing16,17-isoxazoline steroids having a 17a-hydroxy-165,17B-isoxalineconfiguration which compounds are produced in a basic medium in contrastto the acidic medium of the process of the present invention. The typeof compound produced in the said patent can be described as a,a whilethe compound of the present application can be described as [3,,8.Comparison of the UV spectra also show this distinction and thestructural difference is further emphasized by the differentphysiological activities; estrogenic for the compound of Pat. 3,213,084and no substantial estrogenic activity for the compound of the presentapplication.

The novel hypocholesterolemic compositions of the invention having nosubstantial estrogenic activity are comprised of at least one16a,17ot-is0xazolino steroid of the formula OR Z l O n, on

wherein R, R R and Z have the above definitions and a major amount of apharmaceutical carrier. The said compositions may be in the form ofinjectable solutions or suspensions, in ampules, in multiple dosefiacons, in the 4 form of tablets, coated tablets, sublingual tablets,capsules and suppositories prepared in the usual manner.

The novel method of the invention for treating hypercholesterolemia inmammals comprises administering to the mammals an elfective amount of atleast one 16a,l7aisoxazolino steroid of the formula N Rz H CH wherein R,and R R and Z have the above definitions. The said compounds can beadministered orally, perlingually, transcutaneously or rectally. Theusual daily dose is between 20 and 400'y/kg. for adults depending uponthe method of administration. Since the compounds are useful for thetreatment of hypercholester olemia, they are useful for preventing andcuring arterial disorders, cerebral artheritis, aoritis, coronaritis,chest angina and atheromatosis.

In the following examples there are described several preferredembodiments to illustrate the invention. However, it should beunderstood that the invention is not intended to be limited to thespecific embodiments.

EXAMPLE I Preparation of A '(4',5'-16ot,17a)-isoxazolino-2-fiuoro- A-estratriene-3,17,6-diol Step At Preparation ofZ-fluoro-16-hydroxymethylene- A -estratriene-3,-ol-l7-one.0.6 gm. ofZ-fiuoroestrone (described by Hecher et al., Biochem 2., vol. 338, 1963,page 628) were suspended in 140 cc. of benzene and 18 cc. of ethylformate and 0.8 gm. of sodium hydride were added thereto after which 0.8cc. of methanol were slowly added. The mixture was heated and refluxedfor minutes, cooled and diluted with water. The aqueous alkaline phasewas decanted, washed with a benzene-ether mixture, degasified under anatmosphere of nitrogen and slowly acidified with hydrochloric acid. Theprecipitate formed was vacuum filtered and dried to obtain 1.57 gm. of2-fiuoro-16-hydroxymethylene-A -estratriene-3-ol- 17-one having amelting point of 250 C. The solid, colorless product was soluble indilute aqueous alkalis, in alcohol, benzene and chloroform and insolublein water and dilute aqueous acids.

Step B: Preparation of A -(4',5'-16a,l7a)-isoxazolino 2-fluoro-A-estratriene-3,17fl-diol.1.57 gm. of 2- fiuoro-16-hydroxymethylene-A-estratriene-3-ol 17- one, 35 cc. of ethanol and 0.49 gm. ofhydroxylamine hydrochloride were admixed. The mixture was refluxed for 1hour, neutralized with triethylamine and then cooled, The precipitateformed was vacuum filtered, washed with alcohol and dried to obtain 1gm. of A (4,5'-16ot,17a)-isoxazolino-2-fluoro-A -estratriene-3,l7fi-diolhaving a melting point of 278280 C. and a specific rotation of [a]=-ll10 (c.=0.6% in dimethylformamide).

The product was colorless, solid, soluble in dimethylformamide andinsoluble in water, alcohol, acetone, benzene and chloroform.

Analysis.C H O NF (molecular weight=331.36): Calculated (percent): C,68.86; H, 6.69; N, 4.23. Found (percent): C, 69.2; H, 7.0; N, 4.4.

This product is not described in the literature.

EXAMPLE II Preparation of A -(4',5'-16u,17a)-isoxazolino-3,17B-

dimethoxy-A -estratriene Step A: Preparation of A'-(4,5'-16a,17a)-isoxazolino- 3-methoxy-A estratriene-17/3-ol.5 gm. of 3me thoxy-16-hydroxymethylene-A -estratriene-17 one, obtained by theprocess of Ruggieri et al., Gazz. vol. 93, 1963, page 269, were admixedwith 150 cc. of ethanol and 1.45 gm. of hydroxylamine hydrochloride, andthe mixture was held at reflux for 1 hour after which it was cooled to20 C., neutralized with 2 cc. of triethylamine and concentrated to 50cc. under vacuum and agitation. Then, 150 cc. of water were added to theconcentrated mixture which was then cooled. The precipitate obtained wasvacuum filtered, then washed with water until the Wash waters wereneutral and finally dried under vacuum to obtain 5.23 gm. of a rawproduct which was purified by recrystallization from ethyl acetate toobtain 2.31 gm. (44% yield) of A -(4,5-16a,17a)-isoaxolino-3-methoxy-A-estratriene-175-01 having a melting point of 241242 C. and a specificrotation of [a] ==+1l3 (c.=0.8% in dimethylformamide).

The product occurred in the form of crystalline needles which wereslightly soluble in alcohol and insoluble in water.

Analysis.-C H O N (molecular weight=327.4l): Calculated (percent): C,73.37; H, 7.70; N, 4.28. Found (percent): C, 73.3; H, 7.7; N, 4.4.

Step B: Preparation of A -(4',5'-16u,l7a)-isoxazolino- 3,17B-dimethxy-A-estratriene. gm. of A '-(4',

'5' 16a,l7a) isoxazolino 3 methoxy A -estratriene17,B-ol, obtained inthe preceding step, were dissolved in 500 cc. of acetone and 200 cc. ofdimethylformamide and 75 gm. of silver oxide and 50 cc. of methyliodidewere added thereto. The mixture was agitated for 4 hours under anatmosphere of nitrogen and in the total absence of light and filtered.The precipitate obtained was washed with an acetone-dimethylformamidemixture (1:1), and 2,000 cc. of water were added hereto. Then, theprecipitate was filtered and extracted with methylene chloride. Theorganic phase was washed first with water, then with an aqueous solutionof sodium chloride, dried over sodium sulfate and finally evaporated todryness to obtain 12.7 gm. of an amorphous product which was purified byrecrystallization from ethyl acetate to obtain 3.07 gm. of A-(4',5'-16a,l7u)-isoxazolino-3,17/3-dimethoxy- A -estratriene, having amelting point of 164 C. and a specific rotation of [a] =|l37.6 (c.=1% indimethylformamide) The product obtained occurred in the form ofcrystalline needles, soluble in alcohol and chloroform and insoluble inwater.

Analysis.--C H O N (molecular weight=341.44): (Calculated (percent): C,73.86; H, 7.97; N, 4.11. Found (percent): C, 73.7; H, 7.9; N, 4.3.

Infra-red spectra:

absence of hydroxyl absence of carbonyl Ultra-violet spectra: in ethanolInflection toward 219 m E cm.=273 Inflection toward 229 my E cm.=204 Aat 277-278 ma E cm.=59 a at 286 mp. E cm.=56

Ultra-violet spectra: in ethanol N/ 10 hydrochloric acid Inflectiontoward 220 mu E cm.=265 Inflection toward 229 111,11. E cm.=199 )t at278 mu E cms=58 x at 286 m E cm.=52

This product is not described in the literature.

EXAMPLE III Preparation of A -(4,5'-16a,17u)-isoxazolino-3- methoxy- 17/3-acetoxy-A -estratriene.

1 gm. of A '-(4',5'-16a,17a)-isoxazolino-3-methoxy- 11-estratriene-Ufl-ol, obtained as described in Step A of Example II, wasdissolved in 10 cc. of pyridine and 5 cc. of acetic anhydride and thesolution was allowed to stand for 72 hours under an atmosphere ofnitrogen with agitation at room temperature. Then, the solution waspoured in a mixture of 5 cc. of pyridine and cc. of a water-ice mixtureand agitated for 2 hours. The precipitate was vacuum filtered and washedwith water until the wash waters were neutral. Then the pricipitate wasdissolved in 10 cc. of hot methanol and the solution was treated withcharcoal and filtered. The solution was then concentrated to 8 cc., icedand filtered to obtain 650 mg. of raw product which was purified byrecrystallization from methanol to obtain 400 mg. of A '-(45'- 16a,17u)isoxazolino 3 methoxy 17/3 acetoxy- A -estratriene, having a meltingpoint of 136 C. and a specific rotation of [a] =|17O.8 (c.=0.5% inchloroform) and +l82.6 (c.=0.5% in dimethylformamide).

The product occurred in the form of crystalline needles soluble inchloroform and insoluble in water and alcohol.

Analysis.-C H O N (molecular weight=369.45): Calculated (percent): C,71.50; H, 7.37. Found (percent): C, 7l.3; H, 7.4.

Infra-red spectra: carfbonyl at 1750 cm? This product is not describedin the literature.

EXAMPLE IV Preparation of A (4',5'-16uc,l7ot)-1SOX3ZO11I1013B- ethyl-A-gonatriene-3,17,8-diol Step A: 3-acetoxy-13B-ethyl-A-gonatriene-Uflol.l3 gm. of 13p-ethyl-A- -gonatriene-3,17/3-diol,described in Belgian Pat. No. 657,260, were introduced into 130 cc. ofacetone and after 100 cc. of 0.5 N. sodium hydroxide were added thereto,the mixture was agitated for 5 minutes at 20 C. under an inertatmosphere. The reaction mixture was brought to a temperature of about+10 C. and then 4.65 cc. of acetic acid anhydride were slowlyintroduced. The resulting reaction mixture was cooled to 0 C. andmaintained at this temperature for 1 hour under agitation. Theprecipitate formed was recovered by vacuum filtration, washed with waterand again thoroughly vacuum filtered. Then 65 cc. of acetone were addedand the reaction mixture was cooled to a temperature of about 0 C. Amixture of 130 cc. of water and 26 cc. of 0.5 N sodium hydroxide wasadded thereto and the reaction mixture was agitated for 5 minutes. 1.5cc. of acetic acid anhydride were added and the reaction mixture wasagitated for 15 minutes. Thereafter, 26 cc. of 0.5 N sodium hydroxidewere introduced into the reaction mixture, which was then agitated for 5minutes. Next, 1.1 cc. of acetic acid anhydride was added thereto andthe reaction mixture was agitated for 30 minutes longer at about 0 C.The precipitate formed was vacuum filtered, washed first with wateruntil the wash water was neutral, and dried to obtain 13.74 gm. of 3acetoxy 13B ethyl-A -gonatriene-17,8-01, having a melting point of 153C. and it was utilized as such for the next step of the synthesis.

Step B: 3 acetoxy 13H ethyl-A -gonatrieneone.13 gm. of3-acetoxy-13fi-ethyl-A -gonatriene- -01, prepared as in Step A, wereintroduced into 340 cc. of acetone containing 5% water and then, over aperiod of about 15 minutes, a solution containing 4.05 gm. of chromiumtrioxide and 3.45 cc. of concentrated sulfuric acid in suflicient waterto obtain a solution with a volume of 15 cc., was added. The mixture wasagitated for 15 minutes at a temperature of 0 C. and after the additionof a mixture of 13 cc. of an aqueous solution of sodium bisulfite(density=1.28) and 39 cc. of water, the reaction mixture was poured into800 gm. of ice and 1700 cc. of water. The precipitate formed was vacuumfiltered, washed with water and again vacuum filtered to obtain 13 gm.of raw 3-acetoxy-1318-ethyl-A 8 gonatriene-l7-onc which was utilized assuch for the centrated to a small volume to obtain a first yield of 270next step. mg. of A (4',5'-l6a,17a)-isoxazolino-l3fi-ethyl-A Step C: 135ethyl-A -gonatriene-3-ol-17-one.- gonatriene-3,17fl-diol, having amelting point of 2082l0 13 gm. of 3-acetoxy-1Methyl- -gonatriene-l7-one,C. andaspecific rotation of [oc] =+96i3 (c.=0.5% prepared in Step B,were introduced into 130 cc. of 5 in thylf rm mi l methanol and 5.2 cc.of a 36 B. sodium hydroxide y 2o 25 3 (molficulal W9ight=327-41)Isolution were added thereto. The mixture was agitated Calculated (P UFound for 1 hour at room temperature under an inert atmos- (P U phereafter which a mixture of concentrated hydrochloric B evaporating th othr liquors to dryness, a second acid and Water Was added in Sufficientamount to 10 yield of the product was obtained which afterrecrystalobtain a pH value of 34. The reaction mixture was then lizationfro methanol al o had a melting point of 208- poured into 700 cc. ofwater and 300 gm. of ice, allowed 210 C. 225 mg. of product wererecovered in this way. to remain in contact therewith for 30 minutesafter which The novel compound occurred in the form of white theprecipitate was vacuum filtered, washed with water crystals soluble indilute aqueous alkalis, slightly soluble and dried to obtain 11.05 gm.of raw product which was in alcohol and chloroform and insoluble inwater. recrystallized from acetone to obtain 8.30 gm. of 135- Thecompound is not described in the literature. ethyl-A-gonatriene-3-ol-l7-one having a melting PH ARM ACOLOGIC AL DATA polntof 255 C. and a specific rotation of [11], +116 1 5 =1% i dioxane), (A)Hypocholesterolemic action on the female rat AnaIysiS.C l-I O (molecularweight=284.39); C The test was carried out on groups of female ratshavculated (percent): C, 80.24; H, 8.5. Found (percent): ing an averageWeight of 200 gm Each- 2' 5 80's; l7ot)-isoxazolino-2-fiuoro Ammo)estratriene 3,175- Step D: 13,8-ethyl 16 hydroxymethylene-A diol wasutilized in aqueous suspension and was admingonatriene-3-ol-l7-0ne.l.48gm. of 13B-ethyl-A istered orally at daily doses of 50, 100 and 200 'y/kg. for gonatriene-3-ol-17-one were introduced into 120 cc. of a periodof 10 days to the said animals. A group of anhydrous benzene after which13.5 cc. of ethyl formate, female rats of the same age and weight servedas control. 6 gm. of 50% sodium hydride in oil, cc. of benzene Samplesof blood were taken on the eleventh day with a and 0.2 cc. of anhydrousmethanol were added. The susview to determine the amount of sericsterols and the pension thus formed was agitated overnight at roomanimals were sacrified on the same day. The uterus, liver temperatureunder an atmosphere of nitrogen after which 30 and suprarenal glandswere separated and weighed. The it was heated at reflux for two and ahalf hours. After results are summarized in Table I.

TABLE I Supra- Gain Sorlc Hepatic renal Liver, in body Doses, sterols,sterols, Uterus, glands, percent weight, Groups 'y/kg. g. g. mg. mg. g.percent Control rats... 0 0. 62 2. 39 353 57. 2 4. 04 +11 Treated rats0. 67 395 50. 7 4. 02 +14 100 324 2 63.1 3.84 +2 the reaction mixturewas cooled, a water-ice mixture In another test using the sameprocedure, the comwas added thereto and the aqueous phase, containingthe pounds in Table II were administered to said female rats sodium saltof the forrnylated derivative, was decanated, at the dosages recitedtherein. The percent reduction in washed first with ethyl ether and thenwith petroleum 5 the amount of seric sterols was determined and theresults ether. Next, the aqueous phases were combined, acidified are setforth in Table II. with 4 N hydrochloric acid and agitated for 1 hour.

The resulting product was vacuum filtered, washed with TABLE H water anddried to obtain 1.38 gm. of 13,6-ethyl-l6-hy- Reduction in amountsofseric sterols in droxymethylene-A -gonatriene-3-ol-17-one having apercent melting point of 100-110 C. The white product was 50 'y/kg. 100/kg. 200 'yfkg. 500 'y/kg. soluble in dilute aqueous alkalis and inchloroform and t o p unds per ay per day per day per day insoluble inwater. A -(4,5-l6a,17a)-isoxa- This compound is not described in theliterature. :gl g fi f;: Step E: Preparation ofA'-"-(4,5'-16a,l7x)-isoxazolino- 6O A '-(4 ,5-16a,1'ia)450W;-l3fl-ethyl- 1a5(10) natriene-3,l7,8-diol.1.28 gm. of sodium acetate and0.4 gm. of hydroxylamine hydrochloride 01 66 -57 -62 58 were introducedinto 10 cc. of ethanol and the suspension fihgig zfiggiisoxawas agitatedfor several minutes at a temperature of 40 )-@5t;ratrie ne 03 -74 C.after which 1.276 gm. of l3fi-ethyl-l6-hydroxymethyl- G5 f 'gg fggg fgfik ene-A -gonatriene-3-ol-17-one in 10 cc. of ethanol A -estratriene44 66 64 were added. The reaction mixture was heated at reflux for 1hour and then was concentrated under vacuum and Tables I and Hdemonstrate that the products of the Water was added thereto Thereactlon mlxture was invention possess a significant and certainhypocholestertated the precipitflte formed vacuum fi 7O olemic activitybeginning with a daily dose of 50-y/kg. washed with water, dried andpurified by sub ecting the product to chromatography through silica gel,the elutiflg Solvent being a benlfim-ethanol-diomm miXtllFe The testcompounds were utilized in suspension in an (362425). The product thuspurified was then dissolved in aqueous dispersant and were administeredorally to groups hot ethyl acetate, and the solution was filtered andcon- 75 of castarted female rats at varying dosages. Vaginal smears (B)Investigation of estrogenic activity-Allen Doisy test were taken eachday starting from the second day of treatment for a period of sevendays. Only those smears formed exclusively of keratinized cells wereretained as positive. The rat unit for A-(4',5'-16a,17u)-isoxazolino2fluoro A -estratriene-3,17fi-diol Was mg;for A '-(4',5- 5 16a,17a) isoxazolino 3 methoxy-A -estratriene- 17,8-01was 1 mg.; for A '-(4,5-16a,17a)-isoxazolino-3- methoxy-17-fl-acetoXy-A-estratriene was about 2 mg.; and for A '-(4',5'-16u,170c)-isoxazolino-3,1713-dimethoxy-A -estratriene was 1 mg.

The said results show that the compounds of the invention are onlyslightly estrogenic, particularly the 2-fluoro derivative wherein therat unit is reached only at a dosage of 10 mg. per rat.

Various modifications of the compounds and process of the invention maybe made without departing from the spirit or scope thereof, and it is tobe understood that the invention is to be limited only as defined in theappended claims.

We claim:

20 1. A 16a,l7a-isoxazoline steroid of the formula OR 2 f O 2. Acompound of claim 1 wherein Z is methyl and R is selected from the groupconsisting of hydrogen and alkyl of 1 to 7 carbon atoms.

4. A compound of claim 1 which is A -(4',5-l6a,17a)-isoXazolino-3,17p-dimethoXy-A -estratriene.

5. A compound of claim 1 which is A '-(4',5',-l6a,l7a)-isoxazolino-3-methoxy-17/3-acetoxy-A -estratriene.

6. A compound of claim 1 which is A '-(4',5'-l6oc,l7a)isoxazolino-13fl-ethyl-A -gonatriene-3, l76-diol,

7. A process for the preparation of a compound of claim 1 whichcomprises reacting in an acid media a 16- -hydroxymethylene 13fl-Z-A-gon-atriene-l7-one of the formula wherein R R and Z have thedefinitions of claim 1 with a compound selected from the groupconsisting of hydroxylamine and its acid addition salts to form thecorresponding 16:1,17a-isoxazoline steroid of claim 1.

References Cited UNITED STATES PATENTS 3,213,084 10/1965 Schaub et al260239.5

HENRY A. FRENCH, Primary Examiner US. Cl. X.R.

